ABSTRACT
Affecting 12%–18% of women, depending on diagnostic criteria and population studied, polycystic ovary syndrome (PCOS) is prevalent and underrecognized with serious health impacts for affected women and their families. PCOS is the principal cause of anovulatory female infertility and increases the risk of pregnancy complications, such as miscarriage, fetal anomalies, preeclampsia, and gestational diabetes. PCOS is also associated with a range of metabolic features, which include obesity, metabolic syndrome, type 2 diabetes, and cardiovascular risk factors. PCOS is underpinned by insulin resistance. Obesity, more common in PCOS, increases the prevalence and severity of PCOS by exacerbating insulin resistance. Insulin resistance with compensatory hyperinsulinemia affects up to 85% of women with PCOS. Hyperinsulinemia leads to higher ovarian androgen biosynthesis and decreased hepatic sex hormone binding globulin (SHBG) synthesis. The increased local ovarian androgen production augmented by hyperinsulinemia causes premature follicular atresia and anovulation with insulin having reproductive hormonal effects. The contribution of insulin resistance to anovulation in PCOS has led to the introduction of insulin-sensitizing agents as a pharmacological therapy to potentially induce ovulation and enhance fertility. Of the insulin-sensitizing agents, metformin has been most widely studied in women with PCOS since 1994 and has the most reassuring safety profile (1). Metformin is a biguanide, used as an oral antihyperglycemic agent for the prevention and management of type 2 diabetes and is available in two formulations: immediate and extended release (2).
